As Microsoft pushed Outlook.com out of preview mode today, analysts said the company's "Scroogled" attack ads, which fired shots at Google's Gmail two weeks ago, were effective.

"We all like to think that we don't like attack ads, but the fact is, they work," said Peter LaMotte, an analyst with Levick, a Washington-based strategic communications consultancy.

Microsoft has collected less than 10,000 signatures on its anti-Gmail petition, part of its advocacy approach in the latest "Scroogled" campaign.

Today, Microsoft removed the "preview" label from Outlook.com, the company's hope for reclaiming the top spot in the free email service wars. Microsoft is supporting the rebranding effort -- Outlook.com was formerly Hotmail, a nameplate that harks back to 1996 -- with an online and television advertising campaign.

LaMotte, a former ad executive and currently the leader of Levick's digital team, cited last year's groundbreaking real-time surveys of political ads by Vanderbilt University in conjunction with You.gov to support his thesis that attack ads work. Those surveys found that while Americans decried negative political ads, those advertisements were often the most memorable, and presumably the most effective.

Microsoft was roundly criticized by bloggers and pundits for the "Don't Get Scroogled by Gmail" campaign that launched Feb. 7. Todd Bishop, who writes the popular GeekWire blog, asked "Aren't we smarter than this?" Meanwhile, Techcrunch asked, "Why so negative, Microsoft?"

But some saw the campaign as hitting its target, negative be damned.

"I think this is an effective attack," said Ezra Gottheil, an analyst with Technology Business Research, in an email. "I've come to terms with Google's software reading my mail, but it definitely creeps some people out. [And] Gmail is a real threat to Outlook. It is already eating into Outlook's market share, so why not fight back with what you can?"

In October 2012, metrics firm comScore moved Gmail into first place, worldwide, when measured by unique visitors, unseating longtime leader Hotmail.

"And as the Godfather said, this is business," Gottheil said. "Not that companies do not act out of animosity, but this makes sense as a cold-blooded business decision."

But what was interesting about Scroogled was not its attack-dog tone, LaMotte said, but how Microsoft constructed the campaign. "It's really taken an approach more in line with political advocacy campaigns, and under the guidance of Mark Penn, is using the guise of advocacy," he said.

Penn, a longtime political and media strategist who worked as an adviser to former President Bill Clinton during his administration and on Hillary Clinton's 2008 presidential campaign, was hired by Microsoft in mid-2012 to head a strategic special projects group. Penn, who has consulted with Microsoft since 1998, has been credited with creating Scroogled.

"This is more than just an ad, this is a fully realized advocacy campaign," LaMotte said.

Those kinds of campaigns, often run by environmentalists and groups that advocate changes to state and federal constitutions, are characterized not only by advertising, but also by partisan-funded research and grassroots components like petitions.

Don't Get Scroogled by Gmail has all those elements, said LaMotte. "This is far more than just an advertising campaign in the way they're mimicking traditional advocacy," he said.

For the anti-Gmail campaign, Microsoft updated its Scroogled website, ran ads, and urged users to sign an e-petition to "tell Google to stop going through your emails to sell ads." As of Feb. 19, the petition had collected about 38% of the Microsoft-set goal of 25,000 signatures.

Microsoft also commissioned, then cited, a survey that claimed 88% of the 1,000 Americans polled disapproved of email providers scanning messages for ad targeting purposes, and that 89% of those same people felt email services should not be allowed to conduct the practice.

Rather than use Gmail, Microsoft urged people to try Outlook.com, its rebooted, rebranded online email service that launched last July and departed beta today.

Advocacy campaigns are traditionally used to influence opinion about political issues, not technology, LaMotte noted as he put the Scroogled effort into a broader context. "Taking a look from the advocacy aspect, the view is that Washington is now influencing Madison Avenue. Earlier, it was thought that when it comes to elections, Madison Avenue knows how to win hearts and minds. It'll be interesting to see if it works in the other direction."

Scroogled's reliance on an advocacy approach may not be the first for a tech company, but Microsoft's campaign is certainly at a new level, LaMotte said. "It could be more of a timing, cultural move, coming off a [presidential] campaign year, where we saw [advocacy] campaigns like this for the last 16 months," he added, trying to explain why Microsoft went with the strategy.

Google has not directly responded to the Scroogled campaign with one of its own, negative or otherwise, but Gottheil said the search company would -- at some point.

"I expect a response, but I think it makes sense for Google to plan it strategically," said Gottheil. "The company should address the privacy/advertising issue; it's always out there. [But] I don't think Google wants to get into criticizing Outlook beyond its established [total cost of ownership] argument. That's powerful enough, and people know what's wrong with Outlook."

Google has effectively marketed Gmail, Gottheil continued, with its user-based viral approach because of what he said was "enterprise-quality web-based communication and collaboration." It will continue to win hearts, minds and users even if does nothing.

"But if it really wants to move quickly against Outlook, it needs enterprise-level sales, service and support," Gottheil said. "It's a difficult balance to keep that approach from soaking up the savings in TCO, and it is difficult for a company with Google's culture to do it well, but stronger sales, service, and support would hurt Outlook much more."